Portable electronic devices, such as for example, mobile telephones, include features and functionalities that are operated and controlled by the user through a user interface of some type. Such features and functionalities may include for example, game playing, volume control, image capture, and navigation through menus, address books, name lists and other PDA (personal digital assistant) type functions. It is known in the prior art to provide a user input device in the form of an analog joystick or in the form of operation of a combination sequence of two or more keys accessible to the user to carry out the intended function. One major limitation with a user input joystick it is cumbersome and not convenient to hold the portable electronic device while operating the joystick. Although a joystick offers smooth operation, the joystick also adds to the complexity and expense of the device packaging. A problem with key operated user input devices is only a few different selections can be made by the user and then only in discrete steps to provide “on-off” functionality or relatively course adjustment selection. One very popular and sought after feature and functionality by users of mobile telephones is image capture wherein a camera module is integral with the mobile telephone body element. A user typically points the camera module aperture in the desired direction and views the image to be captured on the display screen of the mobile telephone. A designated key or button on the mobile telephone is pressed by the user to operate the camera shutter release to capture the image. Some mobile telephone camera modules include a telephoto functionality to make a distant image appear closer and larger through use of digital zoom or optical zoom techniques, which are well known and understood by those skilled in the imaging capture art. The zoom factor of the telephoto functionality of the camera module is chosen by the user through use of a user input device of some type, such as for example a joystick or key combination operation, to select a desired zoom factor from a number of possible zoom factors. Known prior art user input devices are generally limited for use to select a zoom factor in devices which have only a few different zoom factors available, however, when there are many possible zoom factors available it is difficult to select a desired zoom factor from the many different zoom factors available using a joystick or key combination operation user input device.
A further disadvantage of prior art user input devices, particularly key user input devices, for selecting a desired zoom factor is that many more key combinations are necessary to step through the possible different zoom factors available to select a desired zoom factor. Accordingly, zoom factor selection with prior art user input devices is time sensitive and not smooth when stepping for example from a low zoom factor to a high zoom factor.
It would also be desirable therefore to provide in a portable electronic device camera module a user input device for zoom factor selection that is smooth and continuous over a range of zoom factors to give the “feel” of a single lens reflex (SLR) camera to the user.
Foldable mobile telephones commonly referred to as “flip” or “clamshell” mobile telephones have enclosures wherein a cover pivots or rotates through an angular range with respect to a main body element from a closed operative position to an open operative position. Slidable mobile telephones have enclosures wherein a cover slides or moves along a rectilinear path through a linear range of movement with respect to a main body element from a closed operative position to an open operative position. It would be desirable to take advantage of the continuous motion between the cover and the main body element through at least a portion of the angular range and the linear range respectively such that the cover functions as a user input device.
It is therefore an object of the present invention to provide a user input device in a portable electronic device having a cover and a main body element arranged for movement with respect to one another wherein a signal proportional to and indicative of the relative position between the cover and the main body element is produced to operate an intended function of the portable electronic device.